Communication networks, such as mesh networks, are used to connect a variety of different devices. For example, mesh networks have been employed in the utility industry to connect utility meters, cellular relays, transformers, and/or other nodes. The nodes in the mesh network are typically able to receive data from neighboring nodes and to relay or propagate messages to other neighbor nodes.
In traditional wired networks, a routing metric may be used which rout routes messages based on a fewest number of hops between a source and a destination. In a wireless mesh network, however, a data rate between nodes may vary substantially from one link to another. This variation in data rate may be due, at least in part, to the fact that mesh networks often contain multiple different generations of nodes having different characteristics and capabilities. For example, different generations of nodes may employ or be capable of employing different modulation techniques and/or data rates. This may be particularly true for utility mesh networks in which nodes are placed into service gradually over time and are expected to remain in the field for relatively long life cycles (e.g., 20 years or more). Generally, newer generations of nodes are capable of additional modulations and higher data rates than older generations of nodes.
In addition, in the case of multi-channel networks in which multiple different nodes may be simultaneously transmitting on different channels, some destination nodes may miss transmissions intended for them because they are busy transmitting or receiving on a different channel. Traditionally, a node that sends a message to a destination device that is busy communicating with another device will not receive any response from the destination device. In that case, the node sending the message has no way of knowing if the transmission failed because of a poor link quality, because of a collision (i.e., multiple transmissions on the same channel at the same time), or because the destination device was simply busy communicating with another device on another channel.
Thus, existing routing metrics do not provide an effective way of routing transmissions within a heterogeneous multi-channel wireless mesh network that includes multiple different generations of nodes or nodes otherwise having differing capabilities.